1. Field of the Invention
The present invention relates to a nine-cylinder satellite printing unit having four printing assemblies arranged on a satellite cylinder, each of the printing assemblies containing a form cylinder and a transfer cylinder.
2. Description of the Related Art
Two nine-cylinder satellite printing units which are arranged one above the other in a vertical form of construction are shown in the Manual by Helmut Teschner: Offsetdrucktechnik [Offset Printing Technology] 10th edition, 70736 Fellback: Fachschriften-Verlag, 1997, page 10/32, in FIG. 10. In this assembly, a web is first printed in 4 colors on one side in the lower printing unit and is subsequently fed to the upper printing unit where the web is likewise printed in 4 colors on the reverse side in a second printing. The supply and discharge of the web to and from the satellite cylinder occurs in such a way that the web partially loops around the respective transfer cylinder which is placed at the inflow and outflow and which is in the print throw-off position. The disadvantage of this prior art device is that the transfer cylinder cannot be stopped for a dynamic plate change. The form cylinder and transfer cylinder of each printing assembly of the four printing assemblies of the nine-cylinder satellite printing unit are usually drive-connected mechanically via spur wheels, so that a dynamic plate change is not possible on the printing assemblies arranged on both sides of the web inflow and outflow.
It is an object of the present invention to provide a nine-cylinder satellite printing unit in which a transfer cylinder of a printing assembly may be stopped when a printing assembly is to be switched off for a dynamic plate change.
The object of the present invention is achieved by a nine-cylinder satellite printing unit for receiving and discharging a web to be printed on, wherein a supplied portion of the web is supplied substantially vertically and a discharged portion of the web is discharged substantially vertically. The nine-cylinder satellite printing unit includes a satellite cylinder and first, second, third, and fourth transfer cylinders positioned around the satellite cylinder which form respective printing stations. The first and fourth transfer cylinders are movable between a thrown-on and a thrown-off position relative to the satellite cylinder. Furthermore, a distance between each of the first and second transfer cylinders, the second and third transfer cylinders, and the third and fourth transfer cylinders is smaller than a distance between the first and fourth transfer cylinders. A satellite washing device is arranged between the supplied portion of the web and the discharged portion of the web. An input guide roller proximate the first transfer cylinder guides the supplied portion of the web to the satellite cylinder such that the supplied portion of the web is maintained off of the first transfer cylinder when the first transfer cylinder is in the thrown-off position and an output guide roller proximate the fourth transfer cylinder guides the discharged portion of the web away from the satellite cylinder such that the discharged portion of the web is maintained off of the fourth transfer cylinder when the fourth transfer cylinder is in the thrown-off position. The proposed arrangement of the transfer cylinders of the printing unit and placement of guide rollers for guiding a web run allow the transfer cylinders to be thrown off when the web is running while preserving a satellite washing device, if appropriate.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.